Development of an immunohistochemical method for concurrent staining of releasing hormone (GnRH, TRH, somatostatin, others)-secreting cells and aminergic (norepinephrine and dopamine-secreting) neurons is proposed, using brains of rats and Japanese quail (Coturnix coturnix japonica). Such a method would provide both identification and cytoarchitectural analysis of the specific aminergic systems involved in specific pituitary secretory response patterns. In view of current hypotheses regarding the dual or multiple releasing activities of known releasing and release-inhibiting hormones (RH's), according to which selective anterior pituitary responses require permutative release of two or more RH's, special effort will be made to determine whether any aminergic neurons can be found to have synaptic junctions with more than one type of RH cell. BIBLIOGRAPHIC REFERENCES: Campbell, G.T. and J.A. Ramaley. Ovarian-Dependent Differentiation of a Stimulatory Effect of Dihydrotestosterone (DHT) on Serum FSH in Ovariectomized Rats. Fed. Proc., 1977. Campbell, G.T. and J.A. Ramaley. Maturation of the FSH Control System: Effects of Early Androgenization. Society for the Study of Reproduction, 1977.